QUESTION
Write the negation of the following.
If ∆ABC is not equilateral, then it is not equiangular.
SOLUTION
Let p : ∆ ABC is not equilateral.
q : ∆ ABC is not equiangular.
The given statement is p → q.
Its negation is ~(p → q) ≡ p ∧ ~ q
∴ The negation of given statement is '∆ ABC is not equilateral and it is equiangular'.